In the process of cigarette manufacture, many cigarettes become damaged or the quality of either cigarette paper wrapper or tipping paper does not pass minimum standards to qualify for consumer use. In such cases tobacco in the above-mentioned cigarettes, which is a valuable raw material, needs to be recovered.
Description DE 4119873 presents a construction of an apparatus for tearing the cigarette paper wrapper of the sub-standard filter cigarettes. The above-mentioned device consists of a belt conveyor to transport parallel spaced cigarettes, and of at least one drum used to “open” paper wrappers by means of rotary cutters having tiny teeth located around their perimeter, and those teeth do not damage the cigarette filter tipping paper. Power transmission of the drum is synchronized with the power transmission of the belt conveyor.
Description DE 4446323 discloses an apparatus for recovering tobacco from damaged cigarettes, wherein, behind the conveyor of cigarettes onto which cigarettes are sequentially placed, a cutting device and a sieve for sifting recovered tobacco from the fragments of cut cigarette paper wrapper are used.
Device in accordance with GB 1262664, which is used to “open” rejected cigarettes, has a conveyor and a roller with V-shaped circumferential grooves, the roller being coupled with the conveyor. The grooves have appropriate dimensions so that cigarettes fed lengthwise are clamped between opposite surfaces of the roller's grooves and the conveyor. In this manner the cigarette paper wrapper is ripped and “open” cigarettes are moved to the beating engine, where paper wrapper, tobacco and filter tips are separated.
In one of the constructions of an apparatus for recovery of tobacco from substandard cigarettes which is known from the prior art, the conveyor belt feeds the cigarettes onto the linear vibratory conveyor which moves them towards multiple groove drum conveyor, which transports the cigarettes to the subsequent stations of the apparatus. Cigarettes on the linear vibratory conveyor are moved axially along the direction of movement and are pushed onto the groove drum conveyor, tangentially to its circumference. A rotary cutter with numerous short blades arranged circumferentially is placed over each groove of the drum conveyor. Rotary cutters and drum conveyor rotate, which causes the paper wrapper of the cigarettes in the grooves of the drum conveyor to perforate, whereas, due to precise adjustment of the distance between the cutter blade and the groove surface of the groove conveyor, the cigarette tipping paper is not perforated. The cigarettes processed so move along the drum conveyor and fall on to the vibratory conveyor from where they are moved on to the next station of the process where tobacco is separated from the paper wrapper.
In the known construction of a cigarette perforating assembly, the rotary cutters prick the cigarette, thus perforating its paper wrapper. Some cigarettes get caught against the blades of the rotary cutters, though, and are lifted from the surface of the drum conveyor or linear conveyor and pulled under the clearing shaft, where they tend to fray. Occasionally, some cigarettes lifted from the surface of the conveyor travel over the cutter and once more enter the space between the blades and the groove surface of the drum conveyor. In this situation cigarettes can be perforated again, e.g. when a cigarette is positioned a different way during each cycle of perforation, or when two cigarettes are simultaneously pulled under one cutter.
As a result of issues described above known from the prior art, the mass of tobacco recovered from cigarettes becomes contaminated with small fragments of cigarette paper wrapper, which is a serious shortcoming of the apparatus for recovering tobacco from cigarettes.